1. Field
Exemplary embodiments relate to a display device and a driving method thereof. More particularly, exemplary embodiments relate to a display device that may improve performance of a gate driver and a driving method thereof.
2. Discussion
A display device, such as a liquid crystal display (LCD), an organic light emitting diode (OLED) display, etc., generally includes a display panel having a plurality of pixels and a plurality of signal lines and a driving unit which drives the display panel. Each pixel typically includes a switching element connected to a signal line, a pixel electrode connected thereto, and a counter electrode. The pixel electrode is connected to the switching element, such as a thin film transistor (TFT), and a data voltage is applied to the pixel electrode. The counter electrode is formed on an entire surface of the display panel and a common voltage Vcom is applied thereto. The pixel electrode and the counter electrode may be disposed on the same substrate or different substrates.
The display device usually receives an input image signal from an external graphic controller or any other suitable source. The input image signal carries luminance information of each pixel and each luminance has a determined number. A data voltage corresponding to desired luminance information is applied to each pixel. The data voltage, which is applied to the pixel, is represented as a pixel voltage depending on a difference from a common voltage, which is applied to the common electrode. The pixel displays a luminance, which is indicated by a gray scale of an image signal. In this manner, to prevent image degradation, which may be caused when electric fields of one direction or voltages having the same polarity are applied for a long time, a polarity of a data voltage for a voltage that is a reference for every frame, every row, every column, or every pixel may be inverted.
A conventional driving unit typically includes a gate driver that supplies a gate signal to a display panel, a data driver that supplies a data signal to the display panel, and a signal controller that controls the data driver and the gate driver. It is noted that the gate driver usually includes a shift register that is formed of a plurality of stages, which are subordinately connected to each other. The gate driver receives a driving voltage and a plurality of gate control signals to generate a gate signal. The driving voltage includes a gate-on voltage, which may turn on a switching element, and a gate-off voltage, which may turn off the switching element. The gate control signals may include a scanning start signal STV that indicates to start the scanning and a gate clock signal CLK that controls an outputting timing of a gate-on pulse. The gate driver generates the gate signal, which is input to a gate line, based on the driving voltage and the gate control signal to output the gate signal to the gate line.
Conventionally, the gate driver and the data driver are mounted on a printed circuit board (PCB) in a form of a chip to be connected to the display panel. Alternatively, a chip of the driving unit may be directly mounted on the display panel. It is also noted that a structure in which a gate driver is integrated into the display panel has been developed. These integrated gate drivers do not require high mobility of a thin film transistor channel as a separate chip.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.